Production of N-acetyl Tα1-HSA throughacetylation by RimJ.

Thymosin alpha 1 (Tα1) is an important immunomodulating agent with various clinical applications. The natural form of Tα1 is-acetylated, which was supposed to be related tostability of the hormone. In this study, fusion protein Tα1-HSA was constructed and expressed in. RimJ, a-acetyltransferase from, was also overexpressed and purified to homogeneity.acetylation of Tα1-HSA in the presence of RimJ and acetyl coenzyme A resulted in-acetyl Tα1-HSA. The-acetylation was determined by LC-MS/MS. Kinetic assay indicated that RimJ had a higher affinity to desacetyl Tα1 than to Tα1-HSA. Bioactivity assay revealed fully retained activity of Tα1 when the hormone was connected to the N-terminus of the fusion protein, while the activity was compromised in our previously constructed HSA-Tα1. With fully retained activity and N-terminal acetylation,-acetyl Tα1-HSA was expected to be a more promising pharmaceutical agent than Tα1.